Device and method for mixing mortar with a specific ratio of sand, cement and water

ABSTRACT

A mixing device (1) having at least two concentric tubular elements (2, 3) including an outer tubular element (2) and an inner tubular element (3) inside the outer tubular element, the outer tubular element and the inner tubular element each supplying a liquid (5) or solid products to be mixed together, and a helical member (4) disposed for rotational movement inside the outer tubular element for entrainment of the liquid (5) or solid products, the helical member surrounding the inner tubular element, the outer tubular element including at least one inlet orifice (6a) for introducing the liquid (5) or solid products into the outer tubular element to be entrained by the helical member, and an outlet orifice (7) for delivering a mixture (9) of the liquid and solid products (5, 8) outside the outer tubular element, the inner tubular element (3) having an open end terminating inside the outer tubular element (2) downstream of the inlet orifice (6a) and upstream of the outlet orifice (7), wherein the mixture (9) is mortar, and the mortar is made of sand S, cement C and water W in ratios S/C from 0 to 10 and W/C from 0.1 to 2.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the mixing of a hydraulic binder and ofmineral materials with a liquid. It relates firstly to a use of a devicecomprising at least two concentric tubular elements, the outer tubularelement containing a helical means for entrainment of liquids or solidproducts in the divided state.

More particularly, it relates to a device comprising at least twoconcentric tubular elements, the outer tubular element containing ahelical means for entrainment of liquids or solid products in thedivided state, for example in the form of grains and/or in the powderedstate, the said helical means surrounding the inner tubular element, theouter tubular element comprising at least one inlet orifice for theliquid or solids and one outlet orifice for the mixture of liquid andsolids, the said inner tubular element emerging inside the outer tubularelement downstream of the inlet orifice and upstream of the outletorifice.

2. Background Art

Such known devices (see, for example, patents FR-A-1,436,336 in the nameof M. RASTOIN and FR-A-2,414,952 in the name of M. LIGOUZAT) are usedfor mixing and transporting solid products and liquids for the purposeof a subsequent operation. Nowhere in these documents is there specifieda means for setting these elements so as to form a new composition, noris provision made for dispensing the mixed products.

SUMMARY OF THE INVENTION

The object of the invention is to overcome these drawbacks. To this end,the device which is defined hereinabove is used to obtain a compositionbased on at least one hydraulic binder by semi-continuous mixing of thehydraulic binder with a liquid.

According to other characteristics, the device is used for:

mixing, transporting and dispensing a composition based on a hydraulicbinder, on mineral materials, and on liquid;

dispensing and distributing a composition;

lining a pipe;

manufacturing a pipe.

The subject of the invention is also an installation which allows a usesuch as defined hereinabove.

The said installation includes a device in accordance to the onedescribed hereinabove and it further includes a moving carriagesupporting the said device including metering supply members in theupstream part of the device and a device for controlling andsynchronizing the displacement of the carriage as a function of thesupply.

This installation allows the hydraulic binder to be supplied anddispensed.

According to other characteristics it comprises a rotary axisymmetricelement open at one end, the said rotary element being concentric withand of a greater diameter than the tubular elements of the device.

A further subject of the invention is a method for lining a metal pipebased on quick-setting cement.

According to another characteristic, the lining is based on mortarcontaining a significant proportion of sand.

BRIEF DESCRIPTION OF THE DRAWING FIGURE

A non-limiting example of the invention will now be described withreference to the appended drawing, the single FIGURE of whichdiagrammatically represents an installation for mixing and dispensing ahydraulic binder in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The installation represented in the drawing comprises a device 1 formedof a tubular element 2 concentrically surrounding a second, emerging,tubular element 3. A helical spring 4 contained in the first tubularelement 2 surrounds the second tubular element 3 for conveying water 5.The first tubular element 2 exhibits, on the upper part of its circularenvelope, an inlet orifice 6a and at one end exhibits an inlet orifice6b, its other, open, end forms an outlet orifice 7. The tubular element3 passes through the orifice 6b. Dry materials 8 made up particularly ofminerals, for example sand and a hydraulic binder such as a cement areconveyed via the orifice 6a. The mixing of the dry materials 8 withwater 5 forms a mortar 9 which leaves via the orifice 7.

The device 1 is placed on a carriage 10.

A rotary pipe 11 of an inside diameter greater than the outside diameterof the first tubular element is located level with the open end of thefirst tubular element 2, forming a dispensing injection tube.

The pipe 11 is concentric with the tubular element 2 forming adispensing injection tube. Metering members 12 are connected to theupper inlet orifice 6a. A control and synchronization device 13 makes itpossible to adjust the movements of the installation which comprises amotor 14 for setting into motion hollow rotary bearings 15 forentraining the spring 4. Hoppers 16 containing either cement, or variousminerals such as sand, are located above the metering members 12. A pump17 connected to the tubular element 3 makes it possible to supply thedevice 1 with water.

The tubular element 3 emerges into the tubular element 2 downstream ofthe inlet orifice 6 and upstream of the outlet orifice 7 so as to form,downstream of the outlet from the element 3 a location 18 for mixing drymaterials with water and upstream a zone 19 for transporting and mixingthe dry materials 8. The metering members 12 are connected fixedly tothe carriage 10 by the device 1 and rigid pipelines 20 for conveying thedry materials. A deflector 22 is placed at the end of the spring 4.

The installation dispenses mortar 9 into the pipe 11 by means of thedispensing injection tube 2.

This operation is carried out while simultaneously ensuring the rotationof the pipe 11 on its axis 21, the translation of the device 1, and themixing, transportating into the injection tube 2 and dispensing.

The helical spring 4 placed inside the injection tube 2 is given a fastrotational movement. The dry materials 8 are introduced with controlledflow rates into the zone 19 of the injection tube 2. The spring 4,rotating rapidly, immediately provides vigorous stirring which allowsperfect mixing of the various dry materials 8, as well as transportationof these materials in the injection tube 2 towards the location 18.

The water 5 is injected by means of a second tubular element 3 into thelocation 18 of the feed injection tube 2. There again, the fastrotational movement of the spring 4 ensures perfect mixing of the drymaterials 8 with the water 5 as well as the transportation of the mortar9, thus finished, towards the outlet orifice 7 of the injection tube 2.

At the same time as these mixing operations, the rotational movement ofthe pipe and the translational movement of the injection tube ensureimmediate dispensing of the mortar into the pipe 11 as it leaves thedispensing injection tube 2. The deflector 22 allows even spraying ofthe mortar 9 in order to form a uniform lining of the pipe 11.

A system is therefore available for continuousmixing/transportating/dispensing because the mortar 9 is installedinside the pipe 11 as it is prepared.

This installation exhibits the advantage of being able to limit thequantity of moist mortar 9 present at each instant in the installationwith a location 18 of small size.

Therefore the amount of time that this mortar 9 spends in the device 1is small.

What is more, in the event of an instantaneous halting of the device 1,only the location 18 needs to be cleaned out, the rest of the device 1containing only dry materials.

This installation allows the use of very quick-setting cements. Theminimum setting time for this cement can be as little as 3 minutes. Itis thus possible to use mortars exhibiting a great variation inrheology.

The rheology of the mortar 9 varies depending on the difference in theamount of some of the components with respect to each other. Thus, in acomposition 9 comprising water 5, cement and sand, if there is littlewater 5, the mortar 9 will be very dry, if there is a lot of water 5 thecomposition decants, the solid materials (sand, cement) 8 will fall tothe bottom and the water 5 will rise back up to the surface. It ispossible, in this installation, to mix and to dispense mortarscomprising no sand up to ten times more sand than cement, that is aratio S/C from 0 to 10, S being the sand and C the cement. These mortarsalso lie within a ratio W/C from 0.1 to 2. W being the water 5 and C thecement.

The installation makes it possible to avoid the mortar 9 decantingbecause it does not produce any pressure and stirs the said mortar.

This installation makes it possible, for example, to dispense very drymortars, mortars containing a significant proportion of sand, andmortars which have a high tendency to segregate.

We claim:
 1. A system including a mixing device (1) and a mortar mixedby the mixing device, said system comprising:at least two concentrictubular elements (2, 3) including an outer tubular element (2) and aninner tubular element (3) inside said outer tubular element, said outertubular element and said inner tubular element each supplying one of aliquid (5) and solid products to be mixed together; and a helical member(4) disposed for rotational movement inside said outer tubular elementfor entrainment of the liquid (5) or solid products, said helical membersurrounding said inner tubular element, said outer tubular elementcomprising at least one inlet orifice (6a) for introducing the liquid(5) or solid products into said outer tubular element to be entrained bysaid helical member, and an outlet orifice (7) for delivering a mixture(9) of the liquid and solid products (5, 8) outside said outer tubularelement, said inner tubular element (3) having an open end terminatinginside said outer tubular element (2) downstream of said inlet orifice(6a) and upstream of said outlet orifice (7), wherein said mixture (9)is mortar, and said mortar comprises water W, sand S and cement C as theliquid and solid products, in ratios S/C from 0 to 10 and W/C from 0.1to
 2. 2. A system as recited in claim 1, wherein said outlet orifice (7)of said outer tubular element (2) fits inside a pipe (11) for coating aninner surface of said pipe (11) with said mortar.
 3. A system as recitedin claim 1, further comprising a moving carriage (10) supporting saidouter tubular element (2), and metering supply members (12) in fluidcommunication with said at least one inlet orifice (6a) of said outertubular element (2), and further comprising a device (13) forcontrolling and synchronizing displacement of said moving carriage (10)in accordance with a supply of said solid products.
 4. A system asrecited in claim 1, wherein the cement C is a quick-setting cement.
 5. Amethod for mixing mortar in a mixing device having concentric inner andouter tubular elements, a rotatably mounted helical member in an annularregion between the inner and outer tubular elements, the outer tubularelement having an inlet orifice and an outlet orifice, and the innertubular element having an open end terminating inside the outer tubularelement downstream of the inlet orifice and upstream of the outletorifice, said method comprising:supplying one of a solid component ofthe mortar and a liquid component of the mortar through the inletorifice into the outer tubular element; supplying the other one of thesolid and liquid components of the mortar through the inner tubularelement; rotating the helical member to mix the solid and liquidcomponents in a region of the outer tubular element between the open endof the inner tubular element and the outlet orifice of the outer tubularelement to form the mortar, and to transport the mortar toward theoutlet orifice of the outer tubular element, wherein the solid andliquid components of the mortar comprise sand S, cement C and water W inratios S/C from 0 to 10 and W/C from 0.1 to
 2. 6. A method as recited inclaim 5, wherein the mixing device includes a mobile carriage thatsupports the outer tubular element, said method further comprising thestep of:moving the mobile carriage relative to an object to be coatedwith the mortar.
 7. A method as recited in claim 6, wherein the objectto be coated is a pipe, and said moving step comprises:inserting theoutlet orifice of the outer tubular element to a position inside thepipe for coating an inner surface of the pipe with the mortar.
 8. Amethod as recited in claim 7, wherein the pipe is rotated while theouter tubular element is held stationary.
 9. A method as recited inclaim 6, wherein movement of the mobile carriage is determined inaccordance with a flow rate of the solid component of the mortar.